Ingestion of ethanol (ET) by man generally occurs within a social context and stresses associated with social status are believed to contribute to ingestion of alcohol. The proposed research will contribute important new data on the role of social factors in the control of ET ingestion as well as the role of various predisposing factors (innate level of aggression, innate sensitivity to ET and innate preference for ET). The work also addresses an issue presently unknown - how group housing and social status affect responsiveness to an acute dose of ET. Our long term goal is to determine the neurochemical/neuroendocrine correlates of ET ingestion of group housed rats. Our hypothesis is that social status affects the ingestion of and sensitivity to ET in group housed rats. Water and ET ingestion of group (3 males/colony) or singly housed rats will be monitored continuously. For this, computer interfaced drinkomerers and subcutaneously implanted subject identification microchips will be employed. Experiment I will examine the effect of social status on ET ingestion. Animals will be pretested for their basal preference for ET to determine how innate preference for ET affects subsequent preference for ET and how it relates to subsequently developed social status. There will be 4 groups: group housed/choice of water and ET; group housed/water only; individually housed/choice of water and ET; individually housed/water only. During a 3 week period of group housing, intakes of water and ET and social status will be monitored and animals will be tested for several behavioral correlates: anxiety (elevate plus maze), social interaction, aggression (resident/intruder test) and taste preference. In Experiment II the treatment and testing procedures will be the same as in Experiment I except that animals will be pretested for their level of aggression prior to group housing. Thus, this study will determine the relationship of innate aggression to subsequent development of social status and ET preference. Experiment III's aim is to examine the relationship between innate sensitivity to ET, the development of social status and voluntary ingestion of ET. It will consist of 2 colony (A, B)- and 2 individually (C, D)- housed groups. Animals will be implanted with telemeters to allow continuous monitoring of body temperature. Groups A and C will be used to assess sensitivity to ET and groups B and D to assess BEC produced by the treatment. Using body temperature, animals will be pretested for sensitivity to ET. After a 3 week period of group housing, group A will be treated with 0 (saline), 0.5, 1.0, and 2.0 g/kg using a completely balanced design, and their body temperature will be assessed over a 24 hour period. Animals in group B will be given 2.0 g/kg followed by tail blood sampling for the determination of BEC at 30, 60, 120,240 and 360 minutes.